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Economic chaos, famine, disease, and war may all be attributed to climate change, according to a recent study. Through advances in paleoclimatology, researchers used temperature data and climate-driven economic variables to simulate the climate that prevailed during golden and dark ages in Europe and the Northern Hemisphere from 1500-1800 AD. In doing so, they discovered a set of casual linkages between climate change and human crisis. They noted that social disturbance, societal collapse and population collapse often coincided with significant climate change in America, the Middle East, China, and many other countries in preindustrial times, suggesting that climate change was the ultimate cause of human crisis in many preindustrial societies.

The General Crisis of the 17th Century in Europe was marked by widespread economic distress, social unrest, and population decline. A significant cause of mankind’s woes during these times was the climate-induced shrinkage of agricultural production. Bioproductivity, agricultural production, and food supply per capita all showed immediate responses to changes in temperature. In the five to 30 years following these changes, there were also responses in terms of social disturbance, war, migration, nutritional status, epidemics, and famine.

Cooling during the Cold Phase (1560-1660 AD) reduced crop yields by shortening the growing season and shrinking the cultivated land area. Although agricultural production decreased or became stagnant in a cold climate, population size still grew, leading to an increase in grain price and an increased demand on food supplies. Inflating grain prices led to hardships for many, and triggered social problems and conflicts such as rebellions, revolutions, and political reforms.

Many of these disturbances led to armed conflicts, and the number of wars increased 41 percent during the Cold Phase. During the latter portion of the Cold Phase, the number of wars decreased, but the wars lasted longer and were far more lethal—most notable was the Thirty Years War (1618-1648), where fatalities were more than 12 times of the conflicts between 1500-1619.

Famine became more frequent too. Nutrition deteriorated, and the average height of Europeans shrunk 2cm by the late 16th century. As temperatures began to rise again after 1650, so did the average height.

The economic chaos, famine, and war led people to emigrate, and Europe saw peak migration overlapping the time of peak social disturbance. This widespread migration, in conjunction with declining health caused by poor nutrition, facilitated the spread of epidemics, and the number of plagues peaked during 1550-1670, reaching the highest level during the study period. As a result of war fatalities and famine, the annual population growth rate dropped dramatically, eventually leading to population collapse.

In the 18th century, the mild climate improved matters considerably, leading to the speedy recovery of both Europe’s economy and population.

The alternation between periods of harmony and crisis, golden ages and dark ages, closely followed variations in the food supply per capita. Consequently, grain price could be used as an indicator of crisis in preindustrial Europe. Although grain price is dictated by agricultural production and population size, analysis by the researchers shows that temperature change was the real cause behind the grain price, since agricultural production was climate-dependent at the time.

The history of golden and dark ages in Europe is often attributed to sociopolitical factors, which fails to explain the co-occurrence of long-term crises in different countries, at different stages of development, and across different climate zones. Instead, the authors make a compelling case that climate change is the culprit, thanks to a climate-driven economic downturn due to a decreasing food supply. Where there is a shrinking food supply, chaos and misery follow.

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Allie Wilkinson
Allie is a freelance contributor to Ars Technica. She received a B.A. in Environmental Studies from Eckerd College and a Certificate in Conservation Biology from Columbia University's Earth Institute Center for Environmental Sustainability. Twitter@loveofscience

I didn't know people still used the term "dark ages." Hasn't it been recently discovered (in the past 10-20 years) that much of the perceived notions (lack of innovation in the fields of medicine, technology, art, etc.) of "the dark ages" were false and that there were significant discoveries during those time periods.

And a longer growing season + more plant food means a growing food supply.Isn't everone tired of the AGW fear-mongering yet?

You know, that's an incredibly simplistic view. There is a lot of debate in the scientific community about the consequences of AGW and what humanity could do to stop what we've started. The worst case scenario bandied about is loss of coastal and river areas due to flooding which causes mass migrations (which contributes to crowding) and drops in agricultural output (since lots of farm regions border rivers due to easy access to water). Additionally, don't forget prolonged droughts (already seen in Africa and Texas) in regions where the climate is already traditionally very warm. That's the WORST case scenario - massive social upheaval and a tremendous increase in competition for resources which, no doubt, will cost trillions of dollars in capital and human lives. No scientist is guaranteeing this will happen but it certainly should be factored into policy making, don't you think? Scientists traditionally err on the side of caution because when we don't, we're held responsible for some reason (look at the scientists put on trial in Italy for failing to do the impossible and accurately predict an earthquake). Additionally, scientists have modicum of common sense know that if you prepare for the worst case scenario now, you can avoid TONS of pain in the future. Yes, AGW will also open up traditionally icy regions - Canada and Russia might actually become warm enough to play host to agriculture. But does that mean that we should just accept the inevitable and hope it'll play itself out? That sounds incredibly...irresponsible and idiotic to me and very short-sighted.

I think his point is that generally most of the 'bad' agricultural periods were caused by relatively cold weather and that AGW is warming and thus good for crop production.

Weird, Africa and Texas haven't exactly experiences huge surpluses of agriculture. In fact, both are in prolonged droughts. The boost for crop production will be limited to regions that are, right now, too cold for crop production. But the most of humanity's crop production is centered around rivers, which would be subject to flooding, and temperate climates, which would probably become tropical climates which are not tremendously suitable for agriculture. Don't forget about all the erratic weather which would produce prolonged periods of drought and rainy seasons.

But does that mean that we should just accept the inevitable and hope it'll play itself out? That sounds incredibly...irresponsible and idiotic to me and very short-sighted.

No more so than to say the opposite. Without a clear understanding of the costs and benefits, or even any attempt to really rationally account them, it's irresponsible and idiotic and very short-sighted to say we should do one thing or the other.

And a longer growing season + more plant food means a growing food supply.Isn't everone tired of the AGW fear-mongering yet?

You know, that's an incredibly simplistic view. There is a lot of debate in the scientific community about the consequences of AGW and what humanity could do to stop what we've started. The worst case scenario bandied about is loss of coastal and river areas due to flooding which causes mass migrations (which contributes to crowding) and drops in agricultural output (since lots of farm regions border rivers due to easy access to water). Additionally, don't forget prolonged droughts (already seen in Africa and Texas) in regions where the climate is already traditionally very warm. That's the WORST case scenario - massive social upheaval and a tremendous increase in competition for resources which, no doubt, will cost trillions of dollars in capital and human lives. No scientist is guaranteeing this will happen but it certainly should be factored into policy making, don't you think? Scientists traditionally err on the side of caution because when we don't, we're held responsible for some reason (look at the scientists put on trial in Italy for failing to do the impossible and accurately predict an earthquake). Additionally, scientists have modicum of common sense know that if you prepare for the worst case scenario now, you can avoid TONS of pain in the future. Yes, AGW will also open up traditionally icy regions - Canada and Russia might actually become warm enough to play host to agriculture. But does that mean that we should just accept the inevitable and hope it'll play itself out? That sounds incredibly...irresponsible and idiotic to me and very short-sighted.

''does that mean that we should just accept the inevitable and hope it'll play itself out? ''

Yes, just make sure the military is ready to take care of the problems.

In 1500AD there were only around 500 million humans on the whole planet! Now we are pushing seven billion (and on track to push nine billion by 2025!!!).

England (and much of Europe for that matter) used to be heavily forested. Those forests are long gone, and now we are in the process of chopping down the actual lungs of the earth, ie. Rain forests of South America, Central Africa, and Asia. One only has to spend a few minutes on Google Earth to see the very visible changes made by man.

500 years ago we did not have thousands of coal burning plants, millions of acres of burning vegetation (from poor agricultural practices in the developing world), nor did we have the nearly one billion cars and airplanes.

EDIT: oh and I almost forgot to mention the oceans (once BRIMMING with life) are now systematically turning into acid baths best suited to blooms of RED TIDE and endless armies of poisonous jelly fish.

And a longer growing season + more plant food means a growing food supply.Isn't everone tired of the AGW fear-mongering yet?

IMO it's not fear-mongering if it's true. The climate change which this study concentrates on is not AGW -- it's the natural changing of the climate that the earth goes through.

True. But it's absolutely fair to question whether this study was undertaken specifically to generate the accompanying headline.

Agreed, it is fair to question it. In reading the abstract it appears that this causal relationship has been shown in other studies, and this study was done to get a better handle on what might have really happened. On a side note, this study was done completely in China not known for a high output of AWG fear-mongering.

Quote:

Recent studies have shown strong temporal correlations between past climate changes and societal crises. However, the specific causal mechanisms underlying this relation have not been addressed. We explored quantitative responses of 14 fine-grained agro-ecological, socioeconomic, and demographic variables to climate fluctuations from A.D. 1500–1800 in Europe.

But does that mean that we should just accept the inevitable and hope it'll play itself out? That sounds incredibly...irresponsible and idiotic to me and very short-sighted.

No more so than to say the opposite. Without a clear understanding of the costs and benefits, or even any attempt to really rationally account them, it's irresponsible and idiotic and very short-sighted to say we should do one thing or the other.

Yes, moreso than the opposite, because people are actively pursing that "clear understanding" by studying the chemistry, geology, physics, economics, sociology, etc. of various mitigation and sequestration techniques. In order to say nobody understands the costs and benefits, you have to ignore all that work. Stop spreading unneccesary FUD, please.

So does this study say why natural climate change stopped in the early 1800s when human industry started up? Because since then, according to everyone, man is the sole responsible party for the "climate change" we have. It's warming? Humans with their coal! It's cooling? Aerosols and pollution blocking out the sun! It's wetter? Increased particulates in the air causing water condensation! It's drier? Humans chopping down trees and using water! It's all the evil humans fault! There's only one solution: Massive, massive government regulation of everything people do, with the corresponding taxes and communism! Then the human caused climate change will stop as we all go back to the stone age... and I guess natural climate change come back? So the earth gets hotter and colder and wetter and drier anyway? But hey, at least we all have to pay a tax on the air we breathe, so I guess that is a benefit. Oh, and the environmentalists get to fly to Cancun and Copenhagen while the rest of us drive a horse and buggy, IF we are lucky.

I think his point is that generally most of the 'bad' agricultural periods were caused by relatively cold weather and that AGW is warming and thus good for crop production.

Weird, Africa and Texas haven't exactly experiences huge surpluses of agriculture. In fact, both are in prolonged droughts.

You need to throw Oklahoma in with Texas. Between the two of them, cotton production is down almost 50%.

This will eventually result in higher clothing costs(or perhaps the return of polyester?).

In addition, some farmers have switched from peanuts to cotton to take advantage of the increase prices for cotton, which combined with the soggy peanut crops from Georgia, are going to result in a large increase in the price of peanuts(and peanut butter).

But does that mean that we should just accept the inevitable and hope it'll play itself out? That sounds incredibly...irresponsible and idiotic to me and very short-sighted.

No more so than to say the opposite. Without a clear understanding of the costs and benefits, or even any attempt to really rationally account them, it's irresponsible and idiotic and very short-sighted to say we should do one thing or the other.

Yes, moreso than the opposite, because people are actively pursing that "clear understanding" by studying the chemistry, geology, physics, economics, sociology, etc. of various mitigation and sequestration techniques. In order to say nobody understands the costs and benefits, you have to ignore all that work. Stop spreading unneccesary FUD, please.

So does this study say why natural climate change stopped in the early 1800s when human industry started up? Because since then, according to everyone, man is the sole responsible party for the "climate change" we have. It's warming? Humans with their coal! It's cooling? Aerosols and pollution blocking out the sun! It's wetter? Increased particulates in the air causing water condensation! It's drier? Humans chopping down trees and using water! It's all the evil humans fault! There's only one solution: Massive, massive government regulation of everything people do, with the corresponding taxes and communism! Then the human caused climate change will stop as we all go back to the stone age... and I guess natural climate change come back? So the earth gets hotter and colder and wetter and drier anyway? But hey, at least we all have to pay a tax on the air we breathe, so I guess that is a benefit. Oh, and the environmentalists get to fly to Cancun and Copenhagen while the rest of us drive a horse and buggy, IF we are lucky.

Hyperbolic hyperbole is hyperbolic.

No one is saying that humans are the only cause of climate change, just that we are becoming the greatest factor in it.

No one is saying that humans are the only cause of climate change, just that we are becoming the greatest factor in it.

But why is that relevant? If the climate is going to change even in the absence of human factors, then it is not clear why attempting to prevent climate change by curtailing human factors is a sensible policy.

Now, now. You are completely off base. Humans caused global warming much longer than that! How long have we had humans/human like analogues? Neanderthals, anyone? And when they came, the world was in an ice age. Is europe buried under glaciers now? America? No? Then, I submit to you that the REAL global warming was when Homo Erectus and the Neanderthals conducted scorched earth warfare and conquered fire, with the corresponding increase in CO2 as they learned how to barbeque and cook those tasty, tasty Mammoths. So not only did humans end the ice age, we also killed off the mammoths! If we humans can do that with our pointy sticks and spears and flints, imagine how sick and ill the earth is now that we have-gasp!-coal plants! For details, see arcite's post, where any and every thing is our fault. Next week we will explain how life will cease and the Earth turn into a blackened shell, drifting in its orbit around the sun because some human somewhere--get this evil scenario-- failed to use a mercury filled CFL and instead left their incandescent light on. For twenty minutes.

I tell you, we have to stamp out all use of energy (by the proletariat of course, those who are our environmental betters have bought their carbon indulgences and can do whatever the heck they want) or the world will die! And there will be no more bunnies! Please think of the bunnies!

Funny that this is still a field of active research. I remember learning in school, when we discussed the Thirty Years War, that one of the underlying causes was colder climate and shortage of food (there were - of cause - other prominent factors: reformation, tensions between clergy and worldly leaders, tensions within and without the german empire and so on). I checked, my history book was printed in the mid-90's and it really lists colder climate as a factor of the thirty years war. So, in which part is that paper news?

No one is saying that humans are the only cause of climate change, just that we are becoming the greatest factor in it.

But why is that relevant? If the climate is going to change even in the absence of human factors, then it is not clear why attempting to prevent climate change by curtailing human factors is a sensible policy.

The rate at which humans cause climate change to occur is a large factor -- natural climate change does not occur as quickly as what we humans are causing it to.

If cancer is going to kill people without human intervention, then why even try to cure it?

If cancer is going to kill people without human intervention, then why even try to cure it?

It's more like... there's a natural incidence of cancer, plus a higher rate due to exposure to carcinogens and radioisotopes and such (which are largely human-controlled). Do we try to limit exposure to the latter? Of course. Does that mean we can't *also* research the former? Of course not.

My more serious question, and not the rather obvious commentary, is this: What "Natural climate change" has occurred since the 1810's or so? What natural climate change is occurring now? Because I have yet to see anything since the 1980's, aside from Mount Pinatubo, that has not been blamed on humans in some way.

In other words, how the heck would we tell if the polar caps are melting because of natural climate change vis a vis the soccer mom in her SUV? The "rate of change?" How do we know what the natural rate of change is?

And if the earth is warming 3 degrees by itself, and human involvement makes it 3.1 degree, well, that is not worth anything. Instead of the hysteria that some peddle about the end of days, such as arcite above.

By the way, has no one noticed there are FAR more trees in America now than, say, 1880? Because back then, we used charcoal. A lot. And that takes trees. Lots of them. We only use charcoal in two things now, that I'm aware of: steel making and barbeque grills. Not the primary source of heat. So our forests have recovered, quite dramatically, in fact. Hasn't anyone noticed what happens to an empty field over 50 years? It turns, most of the time, into forest. It's not like chopping an acre of trees means it is just barren ground forever more.

Funny that this is still a field of active research. I remember learning in school, when we discussed the Thirty Years War, that one of the underlying causes was colder climate and shortage of food (there were - of cause - other prominent factors: reformation, tensions between clergy and worldly leaders, tensions within and without the german empire and so on). I checked, my history book was printed in the mid-90's and it really lists colder climate as a factor of the thirty years war. So, in which part is that paper news?

I think the idea is, since this became a political issue, and there are plenty of people who are far more interested in using it for that purpose (See Brutha's posts above), it needs to be studied even more exhaustively to prove even more conclusively that what we already knew is correct.

Sort of like the anti-vax movement. We already knew with 99% certainty that certain things were safe, but because of all the FUD, everyone went BACK to the lab so they could prove with 99.99% certainty that everything is ok.

At least this is my interpretation. Another answer might be that science never says "we are done here, we know this for certain", and there is value in confirming what we already know to a greater degree of confidence and accuracy.

If cancer is going to kill people without human intervention, then why even try to cure it?

It's more like... there's a natural incidence of cancer, plus a higher rate due to exposure to carcinogens and radioisotopes and such (which are largely human-controlled). Do we try to limit exposure to the latter? Of course. Does that mean we can't *also* research the former? Of course not.

Do we try to limit exposure to the latter at all costs? No, we don't. In fact, in most cases, we are not willing to pay more than slight costs. In fact, in many cases, people will gladly pay for the privilege.

And a longer growing season + more plant food means a growing food supply.Isn't everone tired of the AGW fear-mongering yet?

Many people clearly do not have a grasp of the scale of the problem we are facing: the loss of coastlines, the near-term depletion of our most valuable commodity (petroleum), the collapse of fisheries globally, a major economic crisis largely spurred by energy issues, and the list goes on. Fear-mongering? Calling attention to these issues is not irresponsible.

Our future may end up being horrific, and it is not the least surprising that people would rather ignore this with, "everything looks just fine from my perspective!" This unwarranted and ill-advised optimism is our undoing.

On the other hand, current popular solutions to the energy crisis remain wholly impractical. Renewables are proving to be very inefficient and costly as they scale up. Yes, the price of solar panels have dropped tremendously, but the real costs lie elsewhere in storage and environmental impact (urban deployment excepted), not to mention major limitations inherent in capacity. There is currently only one near-term practical solution (maybe two if you want to count the IFR, though the technology is not as good as the MSR) to the energy crisis, and that is with a long-forgotten nuclear reactor design from the 60s called the molten salt reactor.

First, historians have long linked droughts and famines to periods of social and political upheaval. This certainly adds new specificity and understanding to the field, but it's not like the mighty, rational scientists swept in and told those silly humanities majors with their books and stories what was what.

Second: AGW trolls (one way or the other) really don't have a place in this thread.. All the research done was for periods prior to any large-scale human intervention. The only relevance would be that changes in climate--whether natural or anthropogenic--can have huge, real, effects on human society, and have in the past. Drawing conclusions as to whether changes in the future will be positive or negative are far out of the scope of the research, at the very least.

Prattling about how your political opponents will surely blame neanderthal exhalations because aren't-THOSE-people-so-stupid should really be beyond the scope of the discussion entirely.

I thought they were going to moderate discussions like this more heavily? I certainly would like that.

No one is saying that humans are the only cause of climate change, just that we are becoming the greatest factor in it.

But why is that relevant? If the climate is going to change even in the absence of human factors, then it is not clear why attempting to prevent climate change by curtailing human factors is a sensible policy.

Are you seriously arguing that natural climate change is just as bad-or-good as natural+anthropogenic climate change? That the magnitude, direction, and time scales of climate change are unimportant? Seriously? What about human-specific effects: black carbon melting glaciers faster than warm air alone would have done? What about oceans becoming less basic because of the increased carbonic acid concentration? The human factors that cool rather than warm have their own effects too, like acid rain from sulfur aerosols (the same particles that are responsible for much global dimming). Does that not matter either?

It's not as simple as "the climate is going to change anyway." You need to stop arguing as though that were the case.

*edit* Screwed up half of this post trying to quote it, but it's not like Brutha is sticking around to read it anymore anyway.

Shorter Volt-aire: Ban those who disagree with AGW. Because I note you only pointed out my posts, but not the doom and gloom of humans destroying everything like arcite and fromhell.

This is a thread about "changing climate." It says so in the title, in the body of the article, and everything. Yet you want to say that attempts to point out that the earth has changed climate on its own with rather dramatic affects on humanity are beyond the pale, and should be moderated.

I asked a question: why do the AGW people assume natural climate change stopped when the first factory started up? And you are saying, in effect, "NO! We can't ask that kind of question in a climate change thread! Ban the deniers!"

In a forum where people have said that people who deny AGW are stupid mouthbreathers, and did not get moderated for so saying, you types should be able to handle a little dissent. But then, dissent isn't very good is it?

Edit to respond to Wheels of confusion: I'm the one being "hysterical," when in the exact same post you blame humans for melting glaciers and destroying the ocean and causing acid rain, and then get offended that I say that is what AGW people parrot? I fail to see how anything I said is, in fact, more hysterical than what others in this thread have said. See arcite. Just because I restate it in a way that sounds "hysterical" doesn't mean you AGW people aren't, in fact, being chicken little yelling hysterically that the temperatures are rising, the temperatures are rising. We must all have a King! And I note you didn't address my question: where is the natural climate change today that is not human caused? Because all I have ever read is how the evil humans are changing nature (and of course, all change in climate is bad, because, well, it must be, I guess). If you think I'm being hysterical, then show me the climate change universally acknowledged as not human caused, even partially, in the last two hundred years. Only volcanoes fit the bill, and even they have people being blamed partially. So where is the totally natural climate change?

I think his point is that generally most of the 'bad' agricultural periods were caused by relatively cold weather and that AGW is warming and thus good for crop production.

Weird, Africa and Texas haven't exactly experiences huge surpluses of agriculture. In fact, both are in prolonged droughts. The boost for crop production will be limited to regions that are, right now, too cold for crop production. But the most of humanity's crop production is centered around rivers, which would be subject to flooding, and temperate climates, which would probably become tropical climates which are not tremendously suitable for agriculture. Don't forget about all the erratic weather which would produce prolonged periods of drought and rainy seasons.

And another blame the drought on AGW post?

FWIW, a slightly warmer climate would extend growing seasons in lots of places, so no, the boost would not be limited to regions that are, right now, too cold for crop production. A longer growing season generally means more productive yields and / or a second crop.